Tumor associated antigens (TAA) are solubilized from plasma membranes of MST (Moloney sarcoma in BN rats), LM2 (Moloney sarcoma in Lewis rats), BC3 and BC5 (sarcomas in BN rats induced by methylcholanthrene). TAA are purified on controlled-pore-glass columns, yielding fractions devoid of viral antigens, fetal antigens and histocompatibility antigens. TAA will also be prepared from the cytosol of these cells by passing the cytosol through an immunoabsorbent column of anti-TAA antibodies. Rabbits and goats are immunized with membrane TAA and cytosol TAA. Cell hybrids are formed between mouse myeloma cells and rat immune spleen cells and are cloned for monoclonal antibodies to these TAA. These monoclonal antibodies will be used to form immuno-absorbent column and to further purify TAA. The relationship between membrane TAA and cytosol TAA will be determined by pulsing with radioactive amino acid followed by cold chase. The usefulness of these homogenous TAA, anti-TAA antibodies and biochemically modified TAA (conjugated to tubercle bacilli, DNP and dodecanoic acid) as vaccines and immunotherapy will be studied.